Introduction to the nutrient calculator for high rainfall pastures in Western Australia

Page last updated: Tuesday, 16 February 2021 - 4:56pm

The linked calculator is only for high rainfall (>600 mm annual) pastures in South West Western Australia. It uses soil sample test results to estimate soil nutrient status and requirements, and the fertiliser rates to supply required nutrients.

This page includes instructions on how to use to the calculator, and links to other sources of information on nutrient management.

Using the nutrient calculator

The nutrient calculator uses soil test results from a representative 0–10 cm soil sample that has been analysed for phosphorus buffering index (PBI), Colwell phosphorus, Colwell potassium, sulphur (KCl-40S) and pH (CaCl2).

Growers can manually enter their soil test results or import the results from a spreadsheet, and produce colour coded reports. The calculator determines nutrient status, and estimates quantities of phosphorus, potassium or sulphur required to increase current soil test values to target values (termed the capital quantity) to achieve a user-defined relative yield.

The calculator uses critical soil test values derived from nutrient response trials across Australia to estimate soil nutrient status. It does not analyse the economics of the estimated nutrients required.

We recommend that you view the linked video, and read the attached instructions before opening the nutrient calculator for the first time.

Guides for using the nutrient calculator

If you have visited this page before, and understand how to use the nutrient calculator, you can go straight to the application.

Open the Nutrient Calculator

Contact information

David Weaver
Robert Summers
+61 (0)8 9535 4140